The GUID Partition Table (GPT) replaces the previous master boot record (MBR). GPT partitions can hold 18 exabytes compared to 2.2TB for the MBR.

What actually happens is that it interprets the GPT partition table incorrectly, and that causes it to get confused about what is where on the disk.

We need to ensure that the partition style is a GUID Partition Table (GPT) or a Master Boot Record (MBR). For that, run list disk. Check if the “Gpt” column contains an asterisk (*).

I want to partition the card so I can use it for an OS install disk (Mac OS Extended GUID) in one partition and as a camera disk (MS-DOS FAT) in the other partition.

Note that this command works only on Intel Macs with hard disks formatted using the GPT (GUID Partition Table) format with a journaled Hierarchical File System Plus (HFS+) file system.